As I've said before, the two Electrofags I have (Titan and Njoy Pro Duo) are not compatible in terms of parts. You can't use the battery for one to drive the smoky parts of the other. You also need separate chargers for each, they don't work with each others' chargers.
However, all is not incompatible. The Titan portable charger thing, which is about the size of a ten-pack of Superkings, will charge Njoy batteries too. This works by pressure so the thread size is irrelevant.
Unfortunately you can't fit Njoy cartridges into the holes provided in the box. Not unless you remove the caps and that would hasten evaporation.
It made me wonder though. There is a market for such a device, charged from USB like the Titan one, with a range of inserts to suit any Electrofag. If someone came up with something like that, they wouldn't be selling any nicotine products at all so the Righteous couldn't touch them. They'd be selling a specialised battery charger.
How about a solar powered one? That's nearly-free electrosmoking, at least in the summer.